a) 2 . 125 . 2002. 8.5 = ( 2 x 5 ) x ( 125 x 8 ) x 2002 = 10 x 1000 x 2002 = 20020000
b) 36 x 42 + 2 x 17 x 18 + 9 x 41 x 6 = 1512 + 612 + 2214 = 4338
c) 28 x 47 + 28 x 43 + 72 x 29 + 72 x 61 = 28 x ( 47 + 43 ) + 72 x ( 29 + 61 ) = 28 x 90 + 72 + 90 = 90 x ( 28 + 72 ) = 90 x 100 = 9000
d) 26 x 54 + 52 x 73 = 1404 + 3796 = 5200
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